Have a home about 20 years old with electric baseboard heat in all the
rooms, except one bedroom and the living room. The last owners
installed a propane fireplace, which we love, but removed the heater
in the living room and then one in the extra bedroom/office. I can't
understand for the life of me why they would remove the heat from the
bedroom although I can understand from the living room.

In the living room my problem is that cold air moves in from the big
window and we probably use more propane than we need to. I have two
solutions. Replace the windows, which are in everyone who has looked
at it's opinion are the original windows, or I thought an easy thing I
can do for very little cost is put the baseboard heat back into room.
While I love the fireplace, its not the most efficient way to heat
this room.

So with all that background I have two questions:

1. What is the difference between the standard electric and the
Hydronic Liquid-Filled heaters.
examples:

http://www.lowes.com/lowes/lkn?actio...546&lpage=none

http://www.lowes.com/lowes/lkn?actio...504&lpage=none


2. The last owner did at least leave the wiring and the wall
thermostat's in both the bedroom and living room. Can I just hook up
new heaters to the existing wiring without any problems?

Also do baseboard heaters loose efficiency over time? If so for as
cheap as they are it might be worth replacing a few others?

Thanks for the input.

John